package com.macro.mall.yg;

public class demo {

    public static void main(String[] args) {
        Integer s1 = new Integer(3);
        Integer s2 = 3;
        Integer s3 = 3;
        Integer s4 = new Integer(s2);
        System.out.println(s1 == s2); //false
        System.out.println(s3 == s2);
        System.out.println(s3.equals(s4));
        System.out.println(s1.equals(s2));    //true
    }
}
